The smoke is still billowing from the US embassy in Tunis following Friday's attack. The fortress-like building, in a posh suburb of the Tunisian capital, was supposed to have been one of the safest places in the country.
There are questions being asked as to how a security breach of this kind could have happened.
One Tunisian blogger I spoke to told me he fears "the image of the Tunisian revolution has been replaced by images of protesters scaling the walls of the US embassy".
Although the Tunisian government is trying to play the incident down, condemning the violence, the atmosphere here remains tense.
On the diplomatic front, this complicates relations between Tunisia and the US.
The US under Barack Obama has stood by the Tunisia's new transitional government, both politically and financially.
Recently, Tunisia's investment and co-operation minister revealed that he expects the US to guarantee at least one fifth of the $2.2-$2.5bn that Tunisia plans to borrow from international markets.
When I first arrived in Tunisia at the beginning of the Arab Spring, Tunisians felt American support for their revolution came very late in the day.
Zine El Abidine Ben Ali, the deposed Tunisian president, was an ally of President George Bush in the US-led "war on terror".
Under anti-terror legislation, Tunisia routinely used torture, illegal detention and unfair trials. Those persecuted under Ben Ali are now among the leaders of the Salafist movement, which encouraged the demonstrations.
Tunisia's interior ministry has threatened to punish all those involved in Friday's embassy attack, and police are hunting a man called Saif Allah bin Hussein, commonly known as Abu Iyad, the leader of a radical wing of the Salafist movement Ansar al-Sharia, or Supporters of Sharia.
The US will be concerned about the ability of Tunisia's government to pacify protests by this outspoken ultraconservative group.